BACKGROUND OF THE INVENTION
Field of the Invention
[0001] The present invention relates to an image forming system that can control electrical
power supplied to peripheral devices connected to an image forming apparatus.
Description of the Related Art
[0002] Copying machines, printers, or facsimile machines are in many cases used with the
electrical power supply being left on all the time. A reduction in the electrical
power consumption of such apparatuses is desirable.
[0003] An electrophotographic image forming apparatus includes a fixing unit that fuses
a toner image onto paper by heat. A fixing unit consumes much of the electrical power
supplied to the image forming apparatus. Thus, it is important to reduce electrical
power consumed by the fixing unit in order to reduce the total electrical power consumption.
Currently, a type of power-saving of the image forming apparatus is widely used, which
has a power-saving mode in which the temperature of the fixing unit is decreased.
Recent image forming apparatuses have a power-saving mode in which, when a second
image forming operation has not been started for a predetermined period of time after
completing first image forming operation, the temperature of the fixing units is decreased.
[0004] Thus, in the power-saving mode, electrical power consumption is reduced by stopping
or reducing the supply of electrical power to the fixing unit. When the power-saving
mode is released, initialization is performed in the image forming apparatus. When
initialization is performed in the image forming apparatus, a fusing temperature,
at which a toner image can be sufficiently fused, needs to be quickly reached by supplying
sufficient electrical power to the fixing unit. However, there is a limit on electrical
power that can be supplied at one time. For example, in Japan, when electrical power
is supplied from an ordinary socket, the maximum electrical power is 1500 W for one
circuit. Thus, when electrical power of 1500 W or more is needed for startup, a special
electrical power line, for example, a specific socket, is needed, thereby significantly
impairing the versatility and installability of the apparatus.
[0005] In view of this problem, an image forming apparatus is proposed in
Japanese Patent Laid-Open No. 2002-014574, which includes a plurality of energy supply units that can supply electrical power
within the image forming apparatus. In such an image forming apparatus, the time of
transition from a power-saving status (power-saving mode) to a standby status (standby
mode) in which said image forming apparatus is ready to start an image forming operation
can be reduced regardless of the power rating of a socket.
[0006] In general, various types of optional device (herein, also called an accessory or
a peripheral device) that expand the functions of an image forming apparatus can be
connected to the image forming apparatus at the user's request. A typical optional
device is a high-capacity paper deck, a stapler unit, a paper folding unit, a sorting
unit, a punching unit, an inserting unit, a cutting unit, an automatic document feeder,
or a glossing unit. A high-capacity paper deck can feed a large number of sheets of
paper. A stapler unit staples sheets of paper on which images are formed. A paper
folding unit folds sheets of paper. A sorting unit sorts sheets of paper. A punching
unit punches holes in sheets of paper. An automatic reversing document feeder is used
when images are formed on both sides of a sheet of paper. An inserting unit inserts
sheets of paper of one type between sheets of paper of another type. A cutting unit
can cut a large number of sheets of paper all at once. An automatic document feeder
automatically feeds a document into a reading position. A glossing unit gives a gloss
to an image formed on a sheet of paper. In general, such optional devices operate
using electrical power supplied from an image forming apparatus to which the optional
devices are connected.
[0007] However, there is a problem with the foregoing known image forming apparatus. Namely,
the image forming apparatus needs to include a high-capacity energy supply unit that
can supply electrical power to a plurality of energy supply units. This increases
the size and cost of the image forming apparatus.
[0008] Furthermore, during initialization of the image forming apparatus, initialization
of optional devices connected to the image forming apparatus is executed in parallel.
In initialization of optional devices, for example, operations of the individual optional
devices and any remaining sheet of paper are checked. Thus, the image forming apparatus
can supply to the fixing unit only as much electrical power as the maximum electrical
power of 1500 W minus electrical power necessary for initialization of the optional
devices.
[0009] Since the optional devices are connected to the image forming apparatus on the user's
request at any time, it is presumed that all of the optional devices are connected
to the image forming apparatus regardless of whether the optional devices are actually
connected to the image forming apparatus. Thus, only as much electrical power as the
maximum electrical power minus electrical power necessary for the optional devices
can be supplied to the fixing unit.
[0010] Although the maximum electrical power is entirely available to the image forming
apparatus when the image forming apparatus is used with no optional device being connected
to the image forming apparatus, sufficient electrical power cannot be used by the
image forming apparatus when such optional devices are connected. That is to say,
since only as much electrical power as the maximum electrical power minus electrical
power necessary to operate all of the optional devices is available, the startup of
the image forming apparatus is delayed, and electrical power consumption and unnecessary
cost are increased.
SUMMARY OF THE INVENTION
[0011] The present invention provides an image forming system that addresses the foregoing
problems.
[0012] The present invention provides an image forming system that can supply sufficient
electrical power to a fixing unit included in an image forming apparatus regardless
of whether any peripheral device is connected to the image forming apparatus.
[0013] The present invention provides an image forming system that includes a secondary
battery that supplies electrical power to peripheral devices so that the secondary
battery is efficiently used.
[0014] According to a first aspect of the present invention, there is provided an image
forming system as specified in the claims.
[0015] Further features of the present invention will become apparent from the following
description of exemplary embodiments with reference to the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Fig. 1 is a longitudinal sectional view showing the structure of an image forming
system according to a first exemplary embodiment.
[0017] Fig. 2 is an external view of an operation unit included in a printer section.
[0018] Fig. 3 is an illustration showing the structures of parts related to electrical power
supplies of a reader section and the printer section.
[0019] Fig. 4 is a flowchart showing the control process of electrical power supply changing.
[0020] Fig. 5 is an illustration showing the structures of parts related to electrical power
supplies of a reader section and a printer section in a second exemplary embodiment.
[0021] Fig. 6 is a flowchart showing the control process of electrical power supply changing.
[0022] Fig. 7 is an illustration showing the structures of parts related to electrical power
supplies of a reader section and a printer section in a third exemplary embodiment.
[0023] Fig. 8 is a flowchart showing the control process of electrical power supply changing.
DESCRIPTION OF THE EMBODIMENTS
[0024] Image forming systems according to exemplary embodiments of the present invention
will now be described with reference to the drawings.
First Exemplary Embodiment
[0025] Fig. 1 is a longitudinal sectional view showing the structure of an image forming
system 1 according to a first exemplary embodiment of the present invention. The image
forming system 1 includes a reader section 10 and a printer section 20. The reader
section 10 is connected to the printer section 20 via a communication cable (not shown).
A controller unit 310 (shown in Fig. 3) in the printer section 20 controls the reader
section 10 via the communication cable. The reader section 10 functions as a peripheral
device of the printer section 20.
[0026] The reader section 10 reads an image of a document and converts the image to image
data. A document feeder 30 that feeds documents is connected to the reader section
10. The body of the reader section 10 includes a scanner unit 104, mirrors 105 and
106, a lens 107, and an image sensor unit 108, for example, a charge coupled device
(CCD), that includes photoelectric transducers. The scanner unit 104 includes a lamp
102 and a mirror 103.
[0027] In the reader section 10, documents held in a tray of the document feeder 30 are
sequentially fed onto a platen glass 101 one by one. When a document is fed into a
predetermined position on the platen glass 101, the lamp 102 in the scanner unit 104
is turned on to emit light beams onto the document while the scanner unit 104 moves
toward the right in the drawing (in the direction of sub-scanning). The light beams
reflected from the document enter the image sensor unit 108 via the mirrors 103, 105,
and 106 and the lens 107. Then, electrical processing, such as, photoelectric conversion,
and general digital processing are performed on the light beams reflected from the
document having entered the image sensor unit 108. The signals having been subjected
to digital processing are output to the printer section 20.
[0028] The printer section 20 forms a visible image on a sheet of paper on the basis of
the input image data. The printer section 20 includes a laser-beam scanner 43, a photoconductive
drum 41, a primary charger 42, a developer unit 44, a paper cassette 47, a transfer
roller 45, a fixing unit 50, paper eject rollers 55, conveying rollers 57 and 59,
and a paper feed roller 58. The photoconductive drum 41 is rotated at a predetermined
peripheral speed (processing speed) in the direction indicated by an arrow k in the
drawing. The photoconductive drum 41 is evenly charged by the primary charger 42 while
it is being rotated.
[0029] The laser-beam scanner 43 emits a laser beam L that is modulated, corresponding to
the image signals from the reader section 10, and the surface of the charged photoconductive
drum 41 is scanned and exposed to the laser beam L. An electrostatic latent image
corresponding to the image data is formed on the photoconductive drum 41 by this operation.
[0030] In the developer unit 44, the electrostatic latent image is subjected to reversal
development using powder toner and visualized as a toner image T. In reversal development,
toner is attracted to an area of the surface of the photoconductive drum 41, the area
having been exposed to the laser beam L.
[0031] Recording material P is fed by the paper feed roller 58 from the paper cassette 47.
The recording material P is conveyed by the conveying rollers 59 and stopped in the
position of the conveying rollers 57. The recording material P is then fed into a
nip (a transfer area) m between the photoconductive drum 41 and the transfer roller
45, to which a transfer bias voltage is applied, in synchronization with the rotation
of the photoconductive drum 41. Then, the toner image T on the photoconductive drum
41 is transferred to a surface of the recording material P by the transfer bias.
[0032] The recording material P, to which the toner image T, which has not been fixed, is
transferred, is removed from the photoconductive drum 41 and fed into the fixing unit
50. The fixing unit 50 includes a heating roller 51 that is maintained at a predetermined
fusing temperature by a temperature controller (not shown) and fixes the toner image
T transferred to the recording material P with the heating roller 51. The recording
material P having been subjected to fixing is ejected to the exterior of the image
forming system 1 by the paper eject rollers 55.
[0033] When a predetermined time has elapsed without an image forming operation being performed
after ejecting the recording material P, on which an image has been formed, the supply
of electrical power to the fixing unit 50, the image forming unit 60, and the like
is stopped or reduced until the next instruction is submitted to perform an image
forming operation, and then the image forming system 1 enters a power-saving status.
In a power-saving status, the fixing unit 50 is maintained at a predetermined temperature
that is lower than the fusing temperature, at which images can be formed.
[0034] Fig. 2 is an external view of an operation unit 70 included in the printer section
20. The operation unit 70 includes a liquid crystal display (LCD) 72 and various types
of key and switch. A touch panel sheet is attached to the surface of the LCD 72. A
system operation screen is displayed on the LCD 72. When a part of the touch panel
corresponding to the position of one of the displayed keys is pressed, the positional
information is sent to the controller unit 310, which is described below. A power
switch 86 for turning on and off a commercial power supply is provided on a side of
the operation unit 70.
[0035] A numeric keypad 78 is used to input figures, such as the number of copies. A start
key 79 is used to start operation (image forming operation) for reading an original
document image. A stop key 80 is used to stop image forming operation in progress.
A reset key 81 is used to reset the input setting using the operation unit 70. A sleep/return
key 84 is used to cause the image forming system 1 to enter a sleep status (the power-saving
mode) or return from a sleep status to a standby status. A guide key 73 is used to
display the description of the function of each key. A copy-mode key 74 is pressed
to cause the image forming system 1 to function as a copying machine. A printer key
77 is used to, for example, configure settings related to print output from an external
device such as a computer.
[0036] Fig. 3 is an illustration showing the structures of parts related to electrical power
supplies of the reader section 10 and the printer section 20. The reader section 10
includes a secondary battery 212 that is charged and discharges electricity and a
pair of electrical power changing switches SW1 and SW2 for supplying electrical power
to a driving unit 215 that includes the scanner unit 104. The secondary battery 212
is a battery that can be electrochemically charged repeatedly, or a capacitor. For
example, a nickel metal hydride battery, a lithium ion battery, or an electric double
layer capacitor may be used. The secondary battery 212 has a function of supplying
electrical power to the reader section 10.
[0037] The foregoing operation unit 70 is connected to the printer section 20. The printer
section 20 includes the controller unit 310, which performs overall control of the
image forming operation, an electrical power supply unit 320, and the like. A central
processing unit (CPU) 311, a read only memory (ROM) 312, a random access memory (RAM)
313, an input/output (I/O) interface 314, which are generally known, and an electrical
power supply I/O interface 315 are connected to the controller unit 310 via a bus
316. The CPU 311 controls the switching operations of the electrical power changing
switches SW1 and SW2 connected to the electrical power supply I/O interface 315 and
controls the on/off state of the electrical power supply unit 320 according to an
electrical power supply control program. This electrical power supply control program
is stored in the ROM 312. The details of the program are described below. Various
types of component necessary for image forming operation are connected to the I/O
interface 314, for example, a paper-size detecting sensor, a thermistor, a high-voltage
control circuit, a beam detecting sensor, and a driving motor. The CPU 311 controls
image forming operations using these components.
[0038] The electrical power supply unit 320 gets electrical power from a commercial power
supply 325 and supplies electrical power to the fixing unit 50, the image forming
unit 60, and another unit 65 in the printer section 20. The image forming unit 60
includes components that perform image forming, for example, the photoconductive drum
41 and the primary charger 42, a control circuit that controls these components, and
an image processing unit. The other unit 65 includes, for example, the paper feed
roller 58, which feeds paper from the paper cassette 47, and a control circuit (not
shown) that controls the operation unit 70. Electrical power is supplied to the controller
unit 310 from an output terminal C. The commercial power supply 325 is provided by
an electrical power company and is an alternating-current power supply of 100 V/15
A in Japan. The electrical power supply unit 320 is activated and stopped in response
to an on/off signal from the electrical power supply I/O interface 315. The magnitude
of the electrical power that is supplied from the electrical power supply unit 320
to each of the fixing unit 50, the image forming unit 60, and the other unit 65 can
be predetermined.
[0039] In the present exemplary embodiment, even when the power switch 86 is turned off,
the controller unit 310 operates in the power-saving mode using a built-in battery
(not shown) and monitors the status of the power switch 86. When the electrical power
supply unit 320 has been activated upon turning on the power switch 86, the controller
unit 310 gets electrical power from the output terminal C of the electrical power
supply unit 320. The controller unit 310 may not include the built-in battery. Alternatively,
the controller unit 310 may be activated at the same time the electrical power supply
unit 320 is activated upon turning on the power switch 86.
[0040] In the printer section 20, during initialization, the electrical power supply unit
320 supplies electrical power to the fixing unit 50, the image forming unit 60, and
the other unit 65. Initialization represents operation during a period between the
time when the electrical power supply of the image forming system 1 has been turned
on or when the power-saving mode has been released and the time when the temperature
of the fixing unit 50 reaches the predetermined fusing temperature (operating temperature).
[0041] The electrical power supply unit 320 supplies electrical power of 1400 W to the fixing
unit 50, out of the maximum electrical power of 1500 W of the commercial power supply
325. The supplied electrical power is used during initialization to, for example,
check the operation of the fixing unit 50, and whether the recording material P is
remaining, and to heat the fixing unit 50. The electrical power supply unit 320 supplies
electrical power of 60 W to the image forming unit 60. The supplied electrical power
is used during initialization to check the status of the photoconductive drum 41,
the laser-beam scanner 43, and the like. The electrical power supply unit 320 supplies
electrical power of 40 W to the other unit 65. This electrical power is used during
initialization to check whether the recording material P is remaining and the status
of the other unit 65. The user can determine the distribution ratio of the electrical
power.
[0042] In the reader section 10, during initialization, the electrical power changing switch
SW1 is switched to contact a (the on side), and the electrical power changing switch
SW2 is switched to contact c (the off side). Electrical power is supplied from the
secondary battery 212 to the driving unit 215 by this operation (refer to a dotted
line L1 in the drawing). In the present exemplary embodiment, electrical power of
80 W is supplied from the secondary battery 212 to the driving unit 215 and used to,
for example, check whether the light source is turned on and the operation of the
reader section 10.
[0043] When the initial check of the individual components has been completed, and when
the temperature of the fixing unit 50 has reached the predetermined fusing temperature,
the image forming system 1 enters standby status in which images can be formed. In
standby status, the electrical power changing switch SW1 is switched to a contact
b (the off side), and the electrical power changing switch SW2 is switched to a contact
d (the on side). The secondary battery 212 is charged with electrical power from the
electrical power supply unit 320 by this operation (refer to a dotted line L2 in the
drawing).
[0044] Then, during image forming operation, the electrical power changing switch SW1 is
switched to the contact b, and the electrical power changing switch SW2 is switched
to the contact c. Electrical power is supplied from the electrical power supply unit
320 to the driving unit 215 by this operation (refer to a dotted line L3 in the drawing).
[0045] Fig. 4 is a flowchart showing the control process of electrical power supply changing.
This processing program is stored in the ROM 312 and executed by the CPU 311 at predetermined
intervals. In step S1, the CPU 311 first determines whether the power switch 86 included
in the operation unit 70 has been turned on or the sleep/return key 84 has been pressed
in the power-saving mode.
[0046] When the CPU 311 determines that the power switch 86 has been turned on or the sleep/return
key 84 has been pressed, the CPU 311 starts initialization. That is to say, in step
S2, the CPU 311 switches the electrical power changing switch SW1 to the contact a
(the on side) and the electrical power changing switch SW2 to the contact c (the off
side) via the electrical power supply I/O interface 315. Electrical power is supplied
from the secondary battery 212 to the driving unit 215 in the reader section 10 by
this operation. At the same time, the electrical power supply I/O interface 315 outputs
an activation signal to the electrical power supply unit 320. The electrical power
supply unit 320 is activated in response to the activation signal and starts to supply
electrical power to the fixing unit 50, the image forming unit 60, and the other unit
65 in the printer section 20 in the foregoing distribution ratio.
[0047] Then, in step S3, the CPU 311 waits until the initial check has been completed and
the temperature of the fixing unit 50 has reached the predetermined fusing temperature,
so that the image forming system 1 enters the standby status in which images can be
formed.
[0048] When the image forming system 1 has entered the standby status, the process proceeds
to step S4. In step S4, the CPU 311 switches the electrical power changing switch
SW1 to the contact b (the off side) and the electrical power changing switch SW2 to
the contact d (the on side) via the electrical power supply I/O interface 315. The
secondary battery 212 is charged with electrical power from the electrical power supply
unit 320 by this operation.
[0049] Then, in step S5, the CPU 311 determines whether image forming operation has been
started by pressing the start key 79 in the operation unit 70. When the CPU 311 determines
that image forming operation has been started, the process proceeds to step S6. In
step S6, the CPU 311 switches the electrical power changing switch SW1 to the contact
b and the electrical power changing switch SW2 to the contact c via the electrical
power supply I/O interface 315. Electrical power is supplied from the electrical power
supply unit 320 to the driving unit 215 in the reader section 10 during image forming
operation by this operation. In this case, electrical power supplied to the fixing
unit 50 in the printer section 20 is reduced as much as electrical power supplied
to the driving unit 215.
[0050] On the other hand, when the CPU 311 determines in step S5 that image forming operation
has not been started, the process proceeds to step S7. In step S7, the CPU 311 sets
the value of a standby flag F set up in the RAM 313 to one and completes the process.
When the CPU 311 determines in step S1 that the power switch 86 has not been turned
on and the sleep/return key 84 has not been pressed, the CPU 311 determines in step
S8 whether the value of the standby flag F is one. When the CPU 311 determines that
the value of the standby flag F is one (when the image forming system 1 is in a standby
status), the process proceeds to step S4. When the CPU 311 determines that the value
of the standby flag F is zero, the CPU 311 completes the process.
[0051] In the image forming system according to the first exemplary embodiment, during initialization,
electrical power is supplied from the secondary battery 212 to the reader section
10, as described above. Thus, sufficient electrical power (1400 W in the present exemplary
embodiment) can be supplied to the fixing unit 50 in the printer section 20 regardless
of whether the reader section 10 is connected to the printer section 20. Accordingly,
the temperature of the fixing unit 50 can be quickly increased to the fusing temperature.
Moreover, the secondary battery 212 is provided in the reader section 10. Thus, unnecessary
cost can be eliminated for a user who does not use the reader section 10 and uses
only the printer section 20. The same advantage can be achieved even when the secondary
battery 212 is provided in optional devices other than the reader section 10.
Second Exemplary Embodiment
[0052] In the image forming system according to the first exemplary embodiment, when a period
during which the image forming system 1 is in a standby status is very short because
the power switch 86 is turned off just after image forming operation has been completed,
the secondary battery 212 may not be charged sufficiently. Thus, when the image forming
system 1 is activated by turning on the power switch 86 just after turning off the
power switch 86, it may be the case that initial check of peripheral devices cannot
be performed due to insufficient charge in the secondary battery 212. Accordingly,
in a second exemplary embodiment, when the secondary battery 212 is not charged sufficiently,
initialization is performed in the reader section 10 using electrical power supplied
from the electrical power supply unit 320 instead of the secondary battery 212.
[0053] Fig. 5 is an illustration showing the structures of parts related to electrical power
supplies of the reader section 10 and the printer section 20 in the second exemplary
embodiment. The same reference numerals as in the first exemplary embodiment are assigned
to corresponding components, and the description of these components is omitted here.
In the second exemplary embodiment, the printer section 20 further includes a capacity
detecting unit 330 that detects the amount of charge in the secondary battery 212.
The capacity detecting unit 330 is connected to the electrical power supply I/O interface
315 in the controller unit 310, and the output from the capacity detecting unit 330
is sent to the CPU 311.
[0054] Fig. 6 is a flowchart showing the control process of electrical power supply changing.
This processing program is stored in the ROM 312 and executed by the CPU 311 at predetermined
intervals. The same step numbers as in the first exemplary embodiment are assigned
to corresponding steps, and the description of these steps is omitted here.
[0055] When the CPU 311 determines in step S1 that the power switch 86 has been turned on
or the sleep/return key 84 has been pressed in the power-saving mode, the process
proceeds to step S1A. In step S1A, the CPU 311 determines whether the amount of charge
in the secondary battery 212 is less than a first predetermined amount. When the CPU
311 determines that the amount of charge in the secondary battery 212 is equal to
or more than the first predetermined amount, the process proceeds to step S2. In step
S2, the CPU 311 switches the electrical power changing switch SW1 to the contact a
(the on side) and the electrical power changing switch SW2 to the contact c (the off
side). Electrical power is supplied from the secondary battery 212 to the driving
unit 215 in the reader section 10 during initialization by this operation. At the
same time, the electrical power supply unit 320 supplies the maximum electrical power
of the commercial power supply 325 to the fixing unit 50, the image forming unit 60,
and the other unit 65 in the printer section 20 in the foregoing distribution ratio.
[0056] On the other hand, when the CPU 311 determines in step S1A that the amount of charge
in the secondary battery 212 is less than the first predetermined amount, the process
proceeds to step S2A. In step S2A, the CPU 311 switches the electrical power changing
switch SW1 to the contact b (the off side) and the electrical power changing switch
SW2 to the contact c (the off side). Electrical power is supplied from the electrical
power supply unit 320 to the driving unit 215 in the reader section 10 during initialization
by this operation.
[0057] In this way, in the image forming system according to the second exemplary embodiment,
even when the secondary battery 212 is not charged sufficiently upon turning on the
power switch 86 or returning from the power-saving mode, the reader section 10 can
perform initialization using electrical power supplied from the electrical power supply
unit 320. Moreover, in a standby status, the secondary battery 212 can be charged
using electrical power from the electrical power supply unit 320, as in the first
exemplary embodiment.
[0058] In the second exemplary embodiment, the capacity detecting unit 330 is provided in
the printer section 20, which is an image forming apparatus. Alternatively, the capacity
detecting unit 330 may be provided in the reader section 10, which is a peripheral
device.
[0059] In the second exemplary embodiment, during initialization, the electrical power supply
that supplies electrical power to the driving unit 215 in the reader section 10 is
changed in response to the amount of charge in the secondary battery 212. Furthermore,
the same control may be performed when the image forming operation has been started.
That is to say, after the CPU 311 determines in step S5 in Fig. 6 that image forming
operation has been started, the CPU 311 may determine whether the amount of charge
in the secondary battery 212 is less than a second predetermined amount. When the
CPU 311 determines that the amount of charge in the secondary battery 212 is less
than the second predetermined amount, the electrical power supply unit 320 in the
printer section 20 supplies electrical power to the driving unit 215 in the reader
section 10. Otherwise, the secondary battery 212 supplies electrical power to the
driving unit 215. Electrical power consumed when the image forming operation is performed
can be reduced by this operation. The second predetermined amount may be the same
as the first predetermined amount or larger than the first predetermined amount.
Third Exemplary Embodiment
[0060] In a third exemplary embodiment, during image forming operation, electrical power
is supplied to the fixing unit 50 from both the electrical power supply unit 320 and
the secondary battery 212. Fig. 7 is an illustration showing the structures of parts
related to electrical power supplies of the reader section 10 and the printer section
20 in the third exemplary embodiment. The same reference numerals as in the second
exemplary embodiment are assigned to corresponding components, and the description
of these components is omitted here.
[0061] In the third exemplary embodiment, an electrical power changing switch SW3 is provided
between the secondary battery 212 and the fixing unit 50. The electrical power changing
switch SW3 is connected to the electrical power supply I/O interface 315 in the controller
unit 310 and is turned on and off in response to an instruction from the CPU 311.
[0062] Fig. 8 is a flowchart showing the control process of electrical power supply changing.
This processing program is stored in the ROM 312 and executed by the CPU 311 at predetermined
intervals. The same step numbers as in the second exemplary embodiment are assigned
to corresponding steps, and the description of these steps is omitted here.
[0063] When the CPU 311 determines in step S5 that image forming operation has been started,
the process proceeds to step S5A. In step S5A, the CPU 311 determines whether the
amount of charge in the secondary battery 212 is less than a predetermined amount.
When the CPU 311 determines that the amount of charge in the secondary battery 212
is equal to or more than the predetermined amount, the process proceeds to step S6A.
In step S6A, the CPU 311 switches the electrical power changing switch SW1 to the
contact b, the electrical power changing switch SW2 to the contact c, and the electrical
power changing switch SW3 to the on position. During image forming operation, electrical
power is supplied to the fixing unit 50 from both the electrical power supply unit
320 and the secondary battery 212 by this operation at the same time electrical power
is supplied to the driving unit 215 in the reader section 10 from the electrical power
supply unit 320.
[0064] On the other hand, when the CPU 311 determines in step S5A that the amount of charge
in the secondary battery 212 is less than the predetermined amount, the process proceeds
to step S6B. In step S6B, the CPU 311 switches the electrical power changing switch
SW1 to the contact b, the electrical power changing switch SW2 to the contact c, and
the electrical power changing switch SW3 to the off position. During image forming
operation, electrical power is supplied to the driving unit 215 in the reader section
10 and the fixing unit 50 only from the electrical power supply unit 320 by this operation.
[0065] In step S6A, electrical power may not be supplied to the driving unit 215 in the
reader section 10 from the electrical power supply unit 320. Alternatively, electrical
power may be supplied to the driving unit 215 from the secondary battery 212. The
predetermined amount used in step S5A during image forming operation may be the same
as or larger than a predetermined amount used in step S1A during initialization.
[0066] In this way, in the image forming system according to the third exemplary embodiment,
when the amount of charge in the secondary battery 212 is equal to or more than the
predetermined amount, sufficient electrical power can be supplied to the fixing unit
50. Thus, a full color image can be formed on thick paper, which easily absorbs heat
of the fixing unit 50, with satisfactory quality. Moreover, electrical power supplied
from the electrical power supply unit 320 to the fixing unit 50 can be reduced as
much as electrical power supplied from the secondary battery 212 to the fixing unit
50. Thus, consumption of electrical power supplied from the commercial power supply
325 can be reduced when an image forming operation is performed.
[0067] The present invention is not limited to the foregoing exemplary embodiments and may
be applied to any other embodiments as far as the functions defined in the claims
and the foregoing exemplary embodiments can be implemented.
[0068] In the foregoing exemplary embodiments, the secondary battery 212 and the electrical
power changing switches SW1 and SW2 are provided in the reader section 10 (an optional
device), and a changing control section (the CPU 311, the electrical power supply
I/O interface 315, and the like in the controller unit 310) is provided in the printer
section 20 (an image forming apparatus). Alternatively, only the electrical power
changing switches SW1 and SW2 may be provided in the printer section 20. Furthermore,
the secondary battery 212 and the electrical power changing switches SW1 and SW2 may
be provided in a device separate from the reader section 10 and the printer section
20.
In the foregoing exemplary embodiments, electrical power is supplied to the reader
section 10 from the secondary battery 212 during initialization. Alternatively, an
electrical power changing switch may be provided in addition to the electrical power
changing switches SW1 and SW2. The electrical power changing switch can combine electrical
power from the secondary battery 212 and electrical power from the electrical power
supply unit 320 and establish a path for supplying the combined electrical power to
the reader section 10. In this case, electrical power supplied from the electrical
power supply unit 320 to the reader section 10 may be smaller than that in a case
where electrical power is supplied to the reader section 10 only from the secondary
battery 212. That is to say, the electrical power supply unit 320 supplies electrical
power that is smaller than electrical power necessary for initialization in the reader
section 10 to the reader section 10. Thus, during initialization, electrical power
supplied from the electrical power supply unit 320 to the fixing unit 50 is just a
little smaller than that in the first exemplary embodiment. Moreover, a period during
which the secondary battery 212 can supply electrical power can be extended.
[0069] In the foregoing exemplary embodiments, the optional (auxiliary) device is a reader
section 10. However, the optional device is not limited to a reader section 10. Another
typical optional device is a paper deck, a stapler unit, a paper folding unit, a sorting
unit, a punching unit, an automatic reversing document feeder, an inserting unit,
a cutting unit, or a glossing unit. Such an optional device includes a secondary battery,
and a driving unit in the optional device performs initial check and the like during
initialization using electrical power from the secondary battery.
[0070] In the foregoing exemplary embodiments, the image forming system 1 is a multi functional
printer (MFP) that has a printing function, a copying function, a scanning function,
and the like. Alternatively, the image forming system 1 may be an ordinary copying
machine, an ordinary printer, or a facsimile machine that has a printing function.
Moreover, the present invention may be applied to a system that includes a plurality
of units or a device that includes a single unit.
[0071] The present invention is also achieved by an embodiment in which a storage medium
that stores program code of software that performs the functions according to the
foregoing exemplary embodiments is provided to a system or a device and a computer
(or a CPU, a micro processing unit (MPU), or the like) included in the system or the
device reads and executes the program code stored in the storage medium.
[0072] In this case, the program code read from the storage medium performs the functions
according to the foregoing exemplary embodiments, and thus the present invention includes
the program code and the storage medium, which stores the program code.
[0073] The following media can be used as storage media that are used to supply the program
code: for example, a floppy disk, a hard disk, a magneto-optical disk, an optical
disk, such as a compact disk ROM (CD-ROM), a CD recordable (CD-R), a CD rewritable
(CD-RW), a digital versatile disk ROM (DVD-ROM), a DVD-RAM, a DVD-RW, or a DVD rewritable
(DVD+RW), a magnetic tape, a nonvolatile memory card, and a ROM. Alternatively, the
program code may be downloaded via networks.
[0074] Moreover, an operating system (OS) operating on a computer may execute some or all
of the actual processing to perform the functions of the foregoing exemplary embodiments
according to instructions from the program code.
[0075] Moreover, the program code read from the storage medium may be written to a memory
included in, for example, a function expansion board inserted in a computer or a function
expansion unit connected to a computer. Then, for example, a CPU included in the function
expansion board, the function expansion unit, or the like may execute some or all
of the actual processing to perform the functions of the foregoing exemplary embodiments
according to instructions from the program code.
[0076] While the present invention has been described with reference to exemplary embodiments,
it is to be understood that the invention is not limited to the disclosed exemplary
embodiments. The scope of the following claims is to be accorded the broadest interpretation
so as to encompass all modifications, equivalent structures and functions.
1. An image forming system (1) includes an image forming apparatus (20) that forms an
image on a sheet and a peripheral device (10) that is connected to the image forming
apparatus, said image forming system comprising:
an electrical power supply unit (320) that, provided in said image forming apparatus,
supplies electrical power to the image forming apparatus and the peripheral device;
a driving unit (215) that, provided in said peripheral device, drives load on the
peripheral device;
a secondary battery (212) that, provided in said peripheral device, supplies electrical
power to the driving unit and is charged with electrical power from the electrical
power supply unit;
an electrical power changing device (SW1, SW2, 315) that activates or deactivates
a first supply path for supplying electrical power from the electrical power supply
unit to the secondary battery and activates or deactivates a second supply path for
supplying electrical power from the secondary battery to the driving unit; and
a controller unit (310) that controls the electrical power changing device so as to
deactivate the first supply path and activate the second supply path when initialization
of the image forming system is performed.
2. The image forming system according to Claim 1,
wherein the electrical power changing device further activates or deactivates a third
supply path (SW3) for supplying electrical power from the electrical power supply
unit to the driving unit, and the controller unit controls the electrical power changing
device so as to deactivate the third supply path when initialization of the image
forming system is performed.
3. The image forming system according to Claim 1,
wherein when the image forming system is in a standby status in which said image forming
apparatus waits for the start of an image forming operation, the controller unit controls
the electrical power changing device so as to activate the first supply path and deactivate
the second supply path to charge the secondary battery.
4. The image forming system according to Claim 1,
wherein the electrical power changing device further activates or deactivates a third
supply path for supplying electrical power from the electrical power supply unit to
the driving unit, and the controller unit controls the electrical power changing device
so as to deactivate the first and second supply paths and activate the third supply
path during image forming operation.
5. The image forming system according to any preceding claim, further comprising:
a capacity detecting unit (330) that detects amount of charge in the secondary battery,
wherein, when initialization of the image forming system is performed, the controller
unit controls the electrical power changing device so as to activate the second supply
path when the amount of charge in the secondary battery detected by the capacity detecting
unit is equal or more than a predetermined amount and deactivate the second supply
path when the amount of charge in the secondary battery is less than the predetermined
amount.
6. The image forming system according to any preceding claim, wherein the image forming
apparatus further includes a fixing unit (50) that fixes a toner image transferred
to a sheet, and the electrical power supply unit supplies electrical power to the
fixing unit when initialization of the image forming system is performed.
7. The image forming system according to Claim 6, further comprising:
a capacity detecting unit that detects amount of charge in the secondary battery;
and
another electrical power changing device that activates or deactivates a fourth supply
path for supplying electrical power from the secondary battery to the fixing unit,
wherein the controller unit controls the other electrical power changing device so
as to activate the fourth supply path when the amount of charge in the secondary battery
detected by the capacity detecting unit is equal to or more than a predetermined amount.
8. The image forming system according to any preceding claim, wherein, when initialization
of the image forming system is performed, the electrical power supply unit supplies
electrical power that is smaller than electrical power required by the driving unit
to the driving unit.
9. The image forming system according to Claim 8,
wherein the electrical power changing device further activates or deactivates a fifth
supply path for combining electrical power from the secondary battery and electrical
power from the electrical power supply unit, and the controller unit controls the
electrical power changing device when initialization of the image forming system is
performed so as to activate the fifth supply path.